Exchange runs well on VMware, however your level of support from Microsoft may vary. Technically they do not support it unless you are a Premier-level customer. They are starting to change their policies to support all virtualization platforms instead of there own. I would call them and not mention the fact that it is running on VMware, they may eventually find out but there is a good chance that they will still assist you. Here is their <a href=”http://support.microsoft.com/?kbid=897615″>official support policy</a>. In addition here is another document from VMware on <a href=”http://www.vmware.com/pdf/exchange_best_practices.pdf”>best practices for running Exchange on VMware</a>.